1. Field
The disclosed embodiments generally relate to a packet-processing technique for communications networks. More specifically, the disclosed embodiments relate to the design of a packet-processing network which is based on a network switch fabric with virtual routers.
2. Related Art
In high-performance systems, a network or input/output (I/O) switch fabric typically plays an important role in traffic movement between servers. For example, with servers running multiple virtual machines (VMs) and many virtualized applications, network-packet streams coming out of a server often include an aggregation of different services that are needed by each of the VMs and their applications. Moreover, when there are a large numbers of servers and VMs in an InfiniBand network fabric, the servers are typically split into multiple subnet domains. In order to communicate between subnets, InfiniBand subnet routing is typically used.
Within this aggregated network pipe, individual network-packet streams (representing different source-destination pairs) tend to have different requirements. Moreover, at times these requirements may be in conflict with each other. For example, one network-packet stream may be associated with communication between two VMs on the same subnet, and another network-packet stream may be associated with communication among different subnets (thereby implying subnet routing). In a typical system, a physical port tends to provide only one type of service, as either a switch or a router. Multiple levels of service usually do not simultaneously exist with granular control of the service level (such as fine-grain routing with higher throughput and lower latency switching and management). Consequently, it can be difficult to maintain the quality of service at the application level throughout the network switch fabric when multiple applications communicate across servers using existing network switch fabrics.
Hence, what is needed is a network switch fabric that facilitates communication of network-packet streams without the problems described above.